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Lander, WY in the 1950s, Courtesy of the Wyoming State Archives

Thank you for visiting the District of Wyoming website.

On this page, you can view the contact information for the office by telephone, by postal mail, or you can contact the Public Affairs Office or the webmaster.




By Telephone

Cheyenne Main Telephone Number: (307) 772-2124
Cheyenne Toll Free Number: (800) 836-5801
Cheyenne Main Facsimile Number (307) 772-2123

Casper Main Telephone Number: (307) 261-5434
Casper Toll Free Number: (800) 809-7066
Casper Main Facsimile Number (307) 261-5471

Lander Main Telephone Number: (307) 332-8195
Lander Toll Free Number: (888) 266-1309
Lander Main Facsimile Number (307) 332-7104

Yellowstone Main Telephone Number: (307) 690-7394
Yellowstone Toll Free Number: (866) 835-9525
Yellowstone Main Facsimile Number (307) 344-9266


Correspondence to the District of Wyoming, including the U.S. Attorney, may be sent to:

Cheyenne Headquarters Office:
United States Attorney’s Office
J.C. O’Mahoney Federal Courthouse
2120 Capitol Avenue, Suite 4000
Cheyenne, WY 82001
For USPS mail only, including job applications:
United States Attorney’s Office
Post Office Box 668
Cheyenne, WY 82003-0668

Casper Branch Office:
United States Attorney’s Office
Dick Cheney Federal Building
100 East "B" Street, Suite 2211
Casper, WY 82601
For USPS mail only:
United States Attorney’s Office
Post Office Box 22211
Casper, WY 82602-5010

Lander Branch Office:
United States Attorney’s Office
331 Main Street, Suite A
Lander, WY 82520
For USPS mail only:
United States Attorney’s Office
Post Office Box 449
Lander, WY 82520-0449

Yellowstone National Park Branch Office, all deliveries:
United States Attorney’s Office
Yellowstone Justice Center
Building #MA-1015, Room 213
Mammoth Hot Springs, WY 82190
For USPS mail only:
United States Attorney’s Office
Post Office Box 703
Yellowstone NP, WY 82190


Office Hours

Office Hours:

The U.S. Attorney’s Office is open for business from 8:00 a.m. to 5:00 p.m., Monday through Friday, except on federal holidays.

Federal Holidays:

Follow this link for a listing of federal holidays that are observed by the federal government and to determine which days the holidays fall upon.


Public Information Officer:

Contact the Public Affairs Officer in Cheyenne or send e-mail to: Public Information Officer



To comment on the District of Wyoming website, please e-mail Webmaster


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